Laundry calender tape



Aug. 4, 1953 w. l. TAYLOR ET AL- 2,647,845

' LAUNDRY CALENDER TAPE Filed July 13, 1950 WI TA 71 0/? a. HAWT/N v 41mm 84 Patented Aug. 4, 1953 LAUNDRY CALENDER TAPE William Ivan Taylor and Selwyn George Hawtin,

Spondon, near Derby, England, assignors to British Celanese Limited, a corporation of Great Britain Application July 13, 1950, Serial No. 173,652 In Great Britain July 21, 1949 1 Claim. 1

This invention relates to textile products and especially to a novel product particularly suitable for use as a laundry calendering tape.

A type of calender in common use in laundrie's comprises a series of cloth-covered rolls rotating in shallow depressions in a hollow steam-heated bed. The damp goods are fed between the first roller and the bed and are carried along the upper surface of the bed and pressed between it and the successive rollers. A calender of the kind referred to is described below with reference to the accompanying drawing. To prevent the fabric sticking to the rollers instead of following the surface of the bed, endless tapes are provided, running between the rollers and the upper surface of the bed. These so-called laundry-calender tapes (which may range in width for example from 0.5 to 1 inch according to the requirements of the particular calender) must be strong, thin, smooth and be capable of being joined without undue thickening, which would leave impressions on the surface of the garments being calendered. They should also be hard-- wearing and resistant to distortion.

We have found that the first two of the requirements set out above can be met much better by a tape of fabric woven from high tenacity regenerated cellulose yarn than by the tapes of woven natural cellulosic fibre commonly used. Such high tenacity regenerated cellulose tapes, however, like the tapes of natural cellulose, are not readily joined satisfactorily without stitching, which necessarily produces an undesirable thickening at the join. We have now found that by providing a tape of high tenacity regenerated cellulose with an overall coating of cellulose acetate, the ends of the tape can subsequently be joined very readily to produce a joint of great strength with little increase in thickness, by applying to the two surfaces to be joined a dilute solution of cellulose acetate in a volatile solvent, pressing the surfaces together and allowing the solvent to evaporate. Moreover, the overall coating of cellulose acetate prolongs the useful life of the tape, reduces any likelihood of fraying in use, and increases the resistance of the tape to distortion by slipping of the threads one over another. Joins made as described, on the tape of the invention, have been found to be over six times as strong as joins made in a similar way on tape of the same regenerated cellulose material which has not had the overall coating of cellulose acetate. lJhe joins Were found not to undergo any apparent weakening on subjection toboiling water for minutes, on scouring for 10 minutes at 75 0., or on ironing at 135 C.

For the tapes of the invention the weight of the fabric before impregnation should range from 1 to 2 oz./square yard.

Th following examples illustrate the production of a laundry-calender tape according to the invention:

Example 1 A ribbon of width 0.5 inch and thickness 0.0032 inch was woven from a warp of 30 denier high tenacity regenerated cellulose yarn and a weft of denier yarn of the same kind, the ends bemg 136 in the half-inch width and the picks to the inch. The regenerated cellulose yarn had atenacity of'above 6 'gms. per denier and was made by saponification of cellulose acetate yarn that had been stretched in moist steam to a tenacity of about 6 gms. per denier. The ribbon was passed through a 6% solution of cellulose acetate in acetone. Excess solution was removed by means of a rubber wiper so as to leave 8-10% of cellulose acetate on the ribbon. The acetone was then evaporated and the ribbon wound up. In use the ribbon was threaded through the calender and the ends joined with a 6% solution of cellulose acetate as described.

Although it is preferred to use a ribbon woven on a ribbon-loom to the desired width, ribbons made by slitting a Widerfabric, for instance by drawing it past stationary or rotating blades, can be used.

Example 2 A fabric of 36 inch width and of the construction specified in Example 1 was impregnated as described in that example, dried, and slid into ribbons by drawing the fabric at a speed of 25 ft./minute past a bank of stationary electrically heated blades spaced at intervals of 0.6 inch across the width of the fabric. During cutting the cellulose acetate was fused along the cut edges by the hot blades. As a consequence of this fusion there is little tendency for unravelling of the fabric to occur in use.

The use of heated blades is not essential since the impregnation alone considerably reduces the tendency to unravel.

An alternative method is to cut the impregnated. fabric into strips while it is in the form of a tightly wound roll, for instance by means of rotating, preferably heated, blades.

The overall coating of cellulose acetate may be heavier than 10% of the weight of the ribbon, for example 12 or even 15%, but such heavy coatings are unnecessary. The coating should not be much lighter than 8%, but considerable improvement over an untreated tape has been obtained with a coating of 6%.

The regenerated cellulose used is preferably made by the process described above. Regenerated cellulose yarn made by other methods, for example by the saponification of cellulose acetate yarn which has been Wet-spun with highstretch, or even regenerated cellulose made by spinning viscose solutions or solutions of cuprammonium cellulose with high-stretch, may be used. The tenacity of the yarn should, however, be at least 3 gms. per denier and it is of advantage for lthe tenacity to be considerably higher, for example at least 4 gms. per denier and preferably above 6 gms. per denier.

The cellulose acetate used in making the regenerated cellulose may have a viscosity in 6% commercial acetone solution at 25 C. ranging from about 90 to 600 centipoises or even higher. In general high viscosity in the cellulose acetate gives superior properties, especially wet-tenacity, in the regenerated cellulose.

Instead of cellulose acetate other thermoplastic cellulose derivatives which are capable of withstanding the conditions of temperature and moisture to which calendering tapes are exposed, may be used. Such derivatives include, for instance, cellulose propionate, cellulose acetatepropionate, cellulose acetate-butyrate, and ethyl cellulose.

The accompanying drawing shows diagrammatically in side elevation a laundry calender of the kind referred to above provided wih tapes according to the invention.

The cast iron bed I has a series of transverse trough-like depressions 2"in its upper surface, each of which accommodates the lower portion of a cloth-covered cast iron roll 3 driven in the direction indicated. The rolls and the bed are heated by means not shown. Endless tapes 4 made according to the invention run between the rolls and the bed and round guide pulleys 5 and B in the direction indicated. The bands are parallel and spaced from one another along the axes of the rolls. An endless cotton blanket i driven by a roll 8 and passing round an apron 9 feeds the goods to the nip ll between the first roll 3 and the bed, whence the goods are carried over the bed by the successive rolls 3. The tapes 4 prevent the goods sticking to the rolls. At the far end [2 of the bed the goods are picked up by an endless cotton blanket i3 and carried under and in contact with the lower surface of the bed. From the blanket l3 the goods are picked up by an endless blanket l4 and carried back between it and the return run of the blanket 13 to a delivery chute I5.

The tapes are made as described in Example 1, their ends being overlapped and bonded together as described in that example after being threaded through the machine.

The invention includes the combination of a calender of the kind referred to provided with tapes of the kind described, their ends being joined by the method described.

The impregnated ribbons of the invention may be used not only as laundry-calender tapes, but also as the tapes in other machines requiring a very thin strong tape the ends of which can be easily and quickly joined without undue thickening at the seam. Cigarette-making machines, for instance, require such tapes and for this purpose the tapes of the invention are very suitable.

Having described our invention, what we desire to secure by Letters Patent is:

An impregnated ribbon suitable for use as a laundry-calender tape, said ribbon being a woven fabric of weight (before impregnation) from 1 to 2 oz./sq. yard and composed of continuous filament regenerated cellulose yarn of denier from to 79 and of tenacity at least 6 gms/ denier, and being impregnated with 8 to 10% of its weight of an impregnant consisting of unplasticized cellulose acetate.

WILLIAM IVAN TAYLOR. SELWYN GEORGE HAWTIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 16,105 Batterson July 7, 1925 1,793,791 Goldman et al Feb. 24, 1931 2,036,424 Malm Apr. 7, 1935 2,043,137 White 1 June 2, 1936 2,169,757 Caldwell Aug. 15, 1939 1,179,571 Banigan Nov. 14, 1939 2,301,664 Eggert et al. Nov. 10, 1942 2,352,747 Whitehead July 4, 1944 2,434,912 Dreyfus et al. Jan. 27, 1948 

